The situation described, where countries with different resources or products engage in trade to meet each other's needs, is commonly referred to as comparative advantage
What is comparative advantage?
In the context of economics, comparative advantage is the ability of a country or individual to produce a particular good or service at a lower opportunity cost than other countries or individuals. This concept is often attributed to the economist David Ricardo.
In your example, if one country specializes in the production of oil and another in agricultural products, they can benefit from trading with each other. Each country focuses on producing the good in which it has a comparative advantage (lower opportunity cost), and then they exchange these goods through international trade.
Complete question
Following WWI. Situation that existed when countries that have one product, like oil, can trade for another product they need, like agricultural products is termed